The present invention relates to an apparatus for making smokable rods having smokable material contained in first and second wrapping materials.
Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge of smokable material such as shredded tobacco (e.g., in cut filler form) surrounded by a wrapping material thereby forming a so-called "smokable rod", "cigarette rod" or "tobacco rod". Normally, a cigarette has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element includes cellulose acetate tow circumscribed by plug wrap, and is attached to the tobacco rod using a circumscribing tipping material.
Cigarettes are employed by the smoker by lighting one end thereof and burning the tobacco within the rod. The smoker then receives mainstream smoke into his/her mouth by drawing on the opposite end (e.g., the filter end) of the cigarette. During the time that the cigarette is burning, sidestream smoke is generated. Sidestream smoke is smoke which directly enters the atmosphere from the lit end of the cigarette. Sidestream smoke diffuses into the atmosphere, and the characteristic visible nature thereof may be perceived negatively by some individuals. The relative amount of visible sidestream smoke generated by burning cigarette is related to the amount of sidestream "tar" generated by the burning cigarette. Typical cigarettes of about 84 mm length (e.g., having a tobacco rod length of about 57 mm and a filter element length of about 27 mm) often yield about 25 to about 35 mg of sidestream "tar" per cigarette. See, Proctor et al, Analyst. Vol. 113, p. 1509 (1988), for an apparatus and technique for determining the sidestream "tar" of a cigarette.
Numerous cigarettes which reportedly yield relatively low levels of visible sidestream smoke have been proposed. For example, cigarettes have been proposed which exhibit extremely low levels of visible sidestreams smoke as well as low levels of sidestream odor by using a smokable material contained in two layers of circumscribing wrapping materials to form a so-called "double-wrapped cigarette rod". See, for example, U.S. Pat. Nos. to Cline et al.; 4,225,636 to Guess U.S. Pat No. 4,561,454; and U.S. patent application Ser. No. 528,802, filed May 24, 1990.
However, the manufacture of double-wrapped cigarettes has several limitations. For example, special equipment is necessary in that commercially available cigarette manufacturing machines (e.g., a Protos cigarette manufacturing machine sold commercially by Hauni-Werke Korber and Co., KG, Hamburg, Germany) are equipped to provide to the garniture region, at a given time, only one layer of wrapping material from one bobbin. A single bobbin could be wound with more than one layer of wrapping material, but the bobbin must be wound carefully to insure that the layers of wrapping materials are in proper alignment to each other. The arrangement is cumbersome and results in the inefficient, slow operation of the cigarette manufacturing machine with the making of numerous low quality cigarettes and high rates of rejected cigarettes.
It would be desirable to provide an apparatus for making such double-wrapped cigarette rods in an efficient and effective manner.